(1R,2S-cis)-2-Hydroxycyclopentanecarboxylic acid ethyl ester |
 |
| Name | (1R,2S-cis)-2-Hydroxycyclopentanecarboxylic acid ethyl ester | ||
| Synonyms | (1R,2S)-2-Hydroxycyclopentanecarboxylic acid ethyl ester | ||
| Name in Chemical Abstracts | Cyclopentanecarboxylic acid, 2-hydroxy-, ethyl ester, (1R,2S)- | ||
| CAS No | 61586-79-6 | ||
| EINECS No | |||
| Molecular formula | C8H14O3 | ||
| Molecular mass | 158.20 | ||
| SMILES code | O[C@@H]1CCC[C@@H]1C(=O)OCC | ||
1H-NMR |
| 1H-NMR: (1R,2S-cis)-2-Hydroxycyclopentanecarboxylic acid ethyl ester | |||
| 500 MHz, CDCl3 | |||
| delta [ppm] | mult. | atoms | assignment |
| 1.19 | t | 3 H | CH3 (ethyl ester) |
| 1.5-2.0 | m | 6 H | CH2 ring |
| 2.54-2.65 | m | 1 H | 1-C-H (CH-COO-) |
| 3.2 | broad s | 1 H | OH |
| 4.08 | q | 2 H | CH2 (ethyl ester) |
| 4.34 | m | 1 H | 2-C-H (CHOH) |
13C-NMR |
| 13C-NMR: (1R,2S-cis)-2-Hydroxycyclopentanecarboxylic acid ethyl ester | |||
| 125.8 MHz, CDCl3 | |||
| delta [ppm] | assignment | ||
| 14.0 | CH3 (ethyl ester) | ||
| 21.8 | C4 | ||
| 26.1 | C5 | ||
| 33.9 | C3 | ||
| 49.5 | C1 | ||
| 60.4 | CH2 (ethyl ester) | ||
| 73.6 | C2 | ||
| 174.6 | C(=O)O- | ||
| 76.5-77.5 | CDCl3 | ||
IR |
| IR: (1R,2S-cis)-2-Hydroxycyclopentanecarboxylic acid ethyl ester | |||
| [Film, T%, cm-1] | |||
| [cm-1] | assignment | ||
| 3480 | O-H valence | ||
| 2973, 2877 | aliph. C-H valence | ||
| 1736 | C=O valence, ester | ||
 |
|  |
Enantioselective synthesis of (1R,2S)-cis-hydroxycyclopentane-carboxylic acid ethyl ester |
| Reaction type: | reduction, stereoselective reduction |
| Substance classes: | carboxylic acid ester, ketone, alcohol, enzyme, natural product |
| Techniques: | stirring with magnetic stir bar, adding dropwise with an addition funnel, working with a thermostat, filtering, evaporating with rotary evaporator, extracting, perforating, rectifying, use of a distillation column, distilling under reduced pressure, heating with oil bath, stirring with a propeller stirrer |
http://www.oc-praktikum.de/nop/en/instructions/pdf/4024_en.pdf
Comments If not fermenting yeast suspensions are used, the batch can possibly be fungous. The filtered solution can not be stored for long and should therefore be immediately extracted. Therefore the used water must be boiled before. During reaction, all reaction containers should be as completely as possible covered. During the extraction, the volume of the aqueous phase increases by 5-7%! To secure a continuous extraction, an appropriate reserve volume must be available in the extraction apparatus.
Waste management Recycling The evaporated diethyl ether is collected and redistilled. Waste disposal Waste Disposal filter residue with Celite solid waste, free from mercury, aqueous phase from extraction solvent water mixtures, halogen free fore-run from distillation organic solvents, halogen free distillation residue organic solvents, halogen free sodium sulfate solid waste, free from mercury Time Preparation of reaction solution: 1 hour Stirring: two days Work up: 5 hours
Simple evaluation indices |
| Atom economy | not defined | ||
| Yield | 55 | % | |
| Target product mass | 8.69 | g | |
| Sum of input masses | 6600 | g | |
| Mass efficiency | 1.3 | mg/g | |
| Mass index | 760 | g input / g product | |
| E factor | 760 | g waste / g product |
Equipment |
 | beaker 10 L |  | addition funnel with pressure balance | |
 | stirring motor and propeller stirrer |  | thermostat with heating coil | |
 | rotary evaporator |  | heatable magnetic stirrer with magnetic stir bar | |
 | distillation apparatus |  | packed column 10 cm | |
 | suction flask |  | suction filter | |
 | apparatus for continuous extraction of a liquid |  | oil bath |
Operating scheme |
 |
Chromatogram |
| GC: crude product | |
| column | DB-1, L=28 m, d=0.32 mm, film=0.25 µm |
| inlet | on column injection |
| carrier gas | H2, 40 cm/s |
| oven | 100°C |
| detector | FID, 270°C |
| integration | percent concentration calculated from relative peak area |
| GC: pure product | |
| column | DB-1, L=28 m, d=0.32 mm, film=0.25 µm |
| inlet | on column injection |
| carrier gas | H2, 40 cm/s |
| oven | 100°C |
| detector | FID, 270°C |
| integration | percent concentration calculated from relative peak area |
Top 10 things to do in Myanmar
There's no place quite like Myanmar. Skyscanner brings you the Top 10 things to do at this undiscovered holiday destination.
Looking for something different? Finally opening up after decades of isolation,Myanmar is
perhaps the last frontier of Southeast Asian travel. This fascinating,
beautiful country is not yet on most travellers' radar, so visit it
before everyone else does!
1. Visit the Shwedagon Pagoda
One the biggest religious monuments in the world, the glittering Shwedagon Pagoda has to be seen to be believed. Built some 2500 years ago to enshrine holy relics of the Buddha, the entire complex is one giant testament to the country's religious faith. Visit at twilight, for extraordinarily atmospheric photos of monks mediating among the golden spires and statues, and marvel at the scale and grandeur of the central stupa. Done with temples for the day? Head out to explore the revitalized and vibrant city of Yangon.
2. Ride a hot-air balloon over Bagan
The rulers of Myanmar's first kingdom showed their might through architecture, in a construction orgy that left behind thousands of temples, pagodas and monasteries scattered over a vast semi-desert plain. This is Myanmar's answer to Cambodia's Angkor Wat, though its spread-out scale means that it's far less crowded. Ride a hot-air balloon to get an unparalleled aerial view, and then rent an electric bike to explore the dusty plains, catch the sunset on top of a pagoda, and perhaps discover your very own deserted temple.
3. Explore the beautiful Inle Lake
One of Myanmar's top tourist destinations, Inle Lake is a gorgeous freshwater lake surrounded by hills and populated by various tribes and wildlife. With its stunningly serene waters, Inle is a picturesque world of floating vegetable gardens, stilt-house villages and rotating markets located among reed-lined canals. Visit the craft workshops of artisan silver, handmade cigars, and extraordinary lotus silk, and see the iconic Intha fishermen as they row their boats with a unique leg-rowing technique. Above all, slow down, chill out, and enjoy the tranquillity.
4. Experience the culture of Mandalay
Steeped in history as the royal capital of Myanmar's golden age, Mandalay is justifiably proud of its cultural heritage. See the walled city of the reconstructed Royal Palace, visit legendary pagodas along the path to Mandalay Hill, and experience the amazing early-morning ritual of washing Buddha's face at the famed Mahamuni Pagoda. Catch performances of puppet shows and classical dance, and shop for antiques and souvenirs in a city well-known for exquisite arts and crafts.
5. Chill out on Ngapali Beach
If you're done with pagodas and temples for a while, head to the gorgeous Ngapali Beach. Here you'll find a stunningly beautiful beach with full-service resorts offering every modern comfort. Spend lazy days sipping fresh coconut juice and lounging on pristine white sands. Need a bit more activity? Other attractions include horseriding or bicycle tours to the nearby fishing villages. For a more local and less expensive experience, check out nearby Ngwe Shaung Beach and Chaungtha Beach.
6. Hike up the pilgrimage path to the Golden Rock
Perched precariously at the edge of a cliff, the gravity-defying Kyaiktiyo, or Golden Rock, is perhaps the third most important pilgrimage site after the Shwedagon Pagoda in Yangon and the Mahamuni Pagoda in Mandalay. Nestled in the hills, the mysterious rock offers some stunning photo opportunities, especially at sunset. Watch devotees as they chant sutras and burn incense, or wander the colourful market town for souvenirs and snacks. While most people take the truck up, there's a shaded pilgrimage path that makes for a delightful day-hike, passing through pleasant villages on the way up.
7. Cross the U Bein Bridge at sunset
Looking for an iconic photo op? It doesn't get any better than this. Less than an hour outside Mandalay lies the famous U Bein Bridge, arguably the oldest and longest teakwood bridge in the world. Famed for its sunsets, the bridge and its surrounding scenery is a much-photographed sight. A pleasant afternoon can be spent on a boat ride across the serene lake, or in the bustle of the crowd, watching the world go by. Combine this with day trips to the nearby former royal capitals of Amapura, Inwa and Sagaing, where fortress ruins, rustic villages, and ancient pagodas await.
8. Escape the heat at Pyin Oo Lwin
During colonial times, the British moved their administrative centre here for good reason - at approximately 1000m above sea level, this pleasant hill station is a welcome respite from the arid heat of the summer season. Explore the beautiful and extensive grounds of the Botanic Gardens, and swim in the clear blue-green waters of the Anisakhan Falls. Just an hour's drive from Mandalay, Pyin Oo Lwin is also famous for its coffee, strawberries and flowers. And for a souvenir, do bring back a bottle of locally-made damson plum wine.
9. Explore the islands of the Mergui Archipelago
Hundreds of pristine, unexplored and uninhabited islands make the Mergui Archipelago one of the world's last hidden tourist destinations. Located in southern Myanmar in the Andaman Sea, the islands were recently opened for tourism, and as of this post, there is only one resort development. Some tour companies offer safari trips or live-aboards, with facilities for diving, snorkelling or just exploring this isolated natural paradise. Get there before it gets developed - perhaps you'll find your own private island. And don't forget to bring along some cold Myanmar Beer!
10. Experience the exuberance of Thingyan
The Water Festival, or Thingyan, takes place in mid-April and is probably the most exciting event in Myanmar. Similar to Songkran in Thailand, it marks the start of the New Year with the practice of throwing water for purification. While a time of retreat and prayer for some, for most it becomes a wild celebration where all hang loose. Especially in the cities, Thingyan is a crazy combination of street party, rock festival, and obstacle course as you try to splash others while avoiding getting splashed. Join the crowd, and forget about staying dry. Bring on the water guns!
1. Visit the Shwedagon Pagoda
One the biggest religious monuments in the world, the glittering Shwedagon Pagoda has to be seen to be believed. Built some 2500 years ago to enshrine holy relics of the Buddha, the entire complex is one giant testament to the country's religious faith. Visit at twilight, for extraordinarily atmospheric photos of monks mediating among the golden spires and statues, and marvel at the scale and grandeur of the central stupa. Done with temples for the day? Head out to explore the revitalized and vibrant city of Yangon.
Come during the day, and stay till late at the Shwedagon Pagoda
2. Ride a hot-air balloon over Bagan
The rulers of Myanmar's first kingdom showed their might through architecture, in a construction orgy that left behind thousands of temples, pagodas and monasteries scattered over a vast semi-desert plain. This is Myanmar's answer to Cambodia's Angkor Wat, though its spread-out scale means that it's far less crowded. Ride a hot-air balloon to get an unparalleled aerial view, and then rent an electric bike to explore the dusty plains, catch the sunset on top of a pagoda, and perhaps discover your very own deserted temple.
Ride a hot-air balloon for a bird's-eye view of Bagan
3. Explore the beautiful Inle Lake
One of Myanmar's top tourist destinations, Inle Lake is a gorgeous freshwater lake surrounded by hills and populated by various tribes and wildlife. With its stunningly serene waters, Inle is a picturesque world of floating vegetable gardens, stilt-house villages and rotating markets located among reed-lined canals. Visit the craft workshops of artisan silver, handmade cigars, and extraordinary lotus silk, and see the iconic Intha fishermen as they row their boats with a unique leg-rowing technique. Above all, slow down, chill out, and enjoy the tranquillity.
Dawn at Inle Lake: a fisherman rows his boat and casts his net
4. Experience the culture of Mandalay
Steeped in history as the royal capital of Myanmar's golden age, Mandalay is justifiably proud of its cultural heritage. See the walled city of the reconstructed Royal Palace, visit legendary pagodas along the path to Mandalay Hill, and experience the amazing early-morning ritual of washing Buddha's face at the famed Mahamuni Pagoda. Catch performances of puppet shows and classical dance, and shop for antiques and souvenirs in a city well-known for exquisite arts and crafts.
5. Chill out on Ngapali Beach
If you're done with pagodas and temples for a while, head to the gorgeous Ngapali Beach. Here you'll find a stunningly beautiful beach with full-service resorts offering every modern comfort. Spend lazy days sipping fresh coconut juice and lounging on pristine white sands. Need a bit more activity? Other attractions include horseriding or bicycle tours to the nearby fishing villages. For a more local and less expensive experience, check out nearby Ngwe Shaung Beach and Chaungtha Beach.
6. Hike up the pilgrimage path to the Golden Rock
Perched precariously at the edge of a cliff, the gravity-defying Kyaiktiyo, or Golden Rock, is perhaps the third most important pilgrimage site after the Shwedagon Pagoda in Yangon and the Mahamuni Pagoda in Mandalay. Nestled in the hills, the mysterious rock offers some stunning photo opportunities, especially at sunset. Watch devotees as they chant sutras and burn incense, or wander the colourful market town for souvenirs and snacks. While most people take the truck up, there's a shaded pilgrimage path that makes for a delightful day-hike, passing through pleasant villages on the way up.
Pilgrims praying and pasting gold leaf on the Golden Rock
7. Cross the U Bein Bridge at sunset
Looking for an iconic photo op? It doesn't get any better than this. Less than an hour outside Mandalay lies the famous U Bein Bridge, arguably the oldest and longest teakwood bridge in the world. Famed for its sunsets, the bridge and its surrounding scenery is a much-photographed sight. A pleasant afternoon can be spent on a boat ride across the serene lake, or in the bustle of the crowd, watching the world go by. Combine this with day trips to the nearby former royal capitals of Amapura, Inwa and Sagaing, where fortress ruins, rustic villages, and ancient pagodas await.
Sunset on the lake, with a view of U Bein Bridge
8. Escape the heat at Pyin Oo Lwin
During colonial times, the British moved their administrative centre here for good reason - at approximately 1000m above sea level, this pleasant hill station is a welcome respite from the arid heat of the summer season. Explore the beautiful and extensive grounds of the Botanic Gardens, and swim in the clear blue-green waters of the Anisakhan Falls. Just an hour's drive from Mandalay, Pyin Oo Lwin is also famous for its coffee, strawberries and flowers. And for a souvenir, do bring back a bottle of locally-made damson plum wine.
9. Explore the islands of the Mergui Archipelago
Hundreds of pristine, unexplored and uninhabited islands make the Mergui Archipelago one of the world's last hidden tourist destinations. Located in southern Myanmar in the Andaman Sea, the islands were recently opened for tourism, and as of this post, there is only one resort development. Some tour companies offer safari trips or live-aboards, with facilities for diving, snorkelling or just exploring this isolated natural paradise. Get there before it gets developed - perhaps you'll find your own private island. And don't forget to bring along some cold Myanmar Beer!
Exploring one of the many islands in the remote Mergui Archipelago
10. Experience the exuberance of Thingyan
The Water Festival, or Thingyan, takes place in mid-April and is probably the most exciting event in Myanmar. Similar to Songkran in Thailand, it marks the start of the New Year with the practice of throwing water for purification. While a time of retreat and prayer for some, for most it becomes a wild celebration where all hang loose. Especially in the cities, Thingyan is a crazy combination of street party, rock festival, and obstacle course as you try to splash others while avoiding getting splashed. Join the crowd, and forget about staying dry. Bring on the water guns!
DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO .....FOR BLOG HOME CLICK HERE
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