Figure 1 Structures of dihydrobenzofuran neolignans 2a and 2b.
Scheme 1 (i) Ag2O, (CH3)2CO:C6H6 3:5, r.t., 20 h (2a: 36% yield; 2b: 43% yield).
Figure 3
Main nuclear Overhauser effect (NOE) correlations observed in the
nuclear Overhauser effect spectroscopy (NOESY) spectra of compounds 2a and 2b.
Table 1 1H and 13C NMR data assignments for compound 2a (400 MHz, CDCl3)
| δCa | δH (integral, multiplicityb), J/ Hz | |
|---|---|---|
| 1 | 132.0 (C) | − |
| 2=6 | 127.5 (CH) | 7.27 (2H, ddd, J2,5 = J6,3 0.3, J2,7 = J6,7 0.6, J2,3 = J6,5 8.3) |
| 3=5 | 115.7 (CH) | 6.84 (2H, dd, J3,6 = J5,2 0.3, J3,2 = J5,6 8.3) |
| 4 | 156.1 (C) | − |
| 7 | 87.7 (CH) | 6.09 (1H, dt, J7,2 = J7,6 0.6, J7,8 7.2) |
| 8 | 55.1 (CH) | 4.27 (1H, dd, J8,6' 1.4, J8,7 7.2) |
| 9 | 170.9 (C) | − |
| 10 | 52.9 (CH3) | 3.83 (3H, s) |
| 1' | 127.8 (C) | − |
| 2' | 130.8 (CH) | 7.43 (1H, ddd, J2',7' 1.1, J2',6' 2.0, J2',3' 8.3) |
| 3' | 110.3 (CH) | 6.89 (1H, dd, J3',6' 0.4, J3',2'8.3) |
| 4' | 161.2 (C) | − |
| 5' | 125.1 (C) | − |
| 6' | 124.9 (CH) | 7.55 (1H, dddd, J6',3' 0.4, J6',7' 0.7, J6',8 1.4, J6',2'2.0) |
| 7' | 144.7 (CH) | 7.66 (1H, ddd, J7',6' 0.7, J7',2' 1.1, J7',8' 15.9) |
| 8' | 115.2 (CH) | 6.32 (1H, d, J8',7' 15.9) |
| 9' | 167.9 (C) | − |
| 10' | 51.7 (CH3) | 3.81 (3H, s) |
bmultiplicities and coupling constant values measured within 1H NMR and J-resolved spectra with the help from1H-1H correlation spectroscopy (COSY) results.
Table 2 2D NMR data for compound 2a (400 MHz, CDCl3)
| C | H | gCOSYa | gHMBCb | gHMQCc | NOESYd |
|---|---|---|---|---|---|
| 1 | – | – | H3 =H5, H7, H8 | – | – |
| 2=6 | 2=6 | H3, H5, H7 | H3 =H5, H7 | H2=H6 | H7, H8 |
| 3=5 | 3=5 | H2, H6 | H5 | H3=H5 | – |
| 4 | – | – | H3 =H5, H2 =H6 | – | – |
| 7 | 7 | H2=H6, H8 | H6, H8 | H7 | H2=H6* |
| 8 | 8 | H7, H6' | H7, H6' | H8 | H2=H6, H6'* |
| 9 | – | – | H7, H8, H10 | – | – |
| 10 | 10 | – | − | H10 | – |
| 1' | – | – | H3', H8' | – | – |
| 2' | 2' | H3', H6', H7' | H6', H7' | H2' | H7', H8'* |
| 3' | 3' | H2', H6' | − | H3' | – |
| 4' | – | – | H2', H3', H6', H7, H8 | – | – |
| 5' | – | – | H8, H3' | – | – |
| 6' | 6' | H2', H3', H7', H8 | H2', H7', H8 | H6' | H8', H7', H8* |
| 7' | 7' | H2', H8', H6' | H2', H6', H8' | H7' | H6'*, H2' |
| 8' | 8' | H7' | H7' | H8' | H6'*, H2' |
| 9' | – | – | H7', H8', H10' | – | – |
| 10' | 10' | – | – | H10' | – |
cgradient-selected heteronuclear multiple quantum coherence;
dnuclear Overhauser effect spectroscopy.
*mean weak correlation.
aGradient-selected correlation spectroscopy;
Table 3 1H and 13C NMR data assignments for compound 2b (400 MHz, acetone-d6)
| δCa | δH (integral, multiplicityb); J/ Hz | |
|---|---|---|
| 1 | 132.5 (C) | – |
| 2 | 111.2 (CH) | 7.10 (1H, ddd, J2,5 0.3, J2,7 0.8, J2,6 2.1) |
| 3 | 149.1 (C) | – |
| 4 | 148.5 (C) | – |
| 5 | 116.3 (CH) | 6.84 (1H, dd, J5,2 0.3, J5,6 8.3) |
| 6 | 120.7 (CH) | 6.92 (1H, ddd, J6,7 0.6, J6,2 2.1, J6,5 8.3) |
| 7 | 88.8 (CH) | 6.04 (1H, ddd, J7,6 0.6, J7,2 0.8, J7,8 7.3) |
| 8 | 57.0 (CH) | 4.47 (1H, dd, J8,6' 1.4, J8,7 7.3) |
| 9 | 172.1 (C=O) | – |
| 10 | 53.5 (CH3) | 3.81 (3H, s) |
| 11 | 56.4 (CH3) | 3.84 (3H, s) |
| 1' | 129.9 (C) | – |
| 2' | 113.9 (CH) | 7.33 (1H, dd, J2',7' 0.4, J2'6' 2.6) |
| 3' | 146.3 (C) | – |
| 4' | 151.5 (C) | – |
| 5' | 127.8 (C) | – |
| 6' | 119.5 (CH) | 7.29 (1H, ddd, J6',7' 0.8, J6',8 1.4, J6',2' 2.6) |
| 7' | 145.9 (CH) | 7.63 (1H, ddd, J7',2' 0.4, J7',6' 0.8, J7',8' 15.8) |
| 8' | 116.8 (CH) | 6.44 (1H, d, J8',7' 15.8) |
| 9' | 168.2 (C) | – |
| 10' | 52.1 (CH3) | 3.73 (3H, s) |
| 11' | 56.8 (CH3) | 3.92 (3H, s) |
bmultiplicities and coupling constant values measured within 1H-NMR and J-resolved spectra with the help from1H-1H correlation spectroscopy (COSY) results.
Table 4 2D NMR data for compound 2b (400 MHz, acetone-d6)
| C | H | gCOSYa | gHMBCb | gHMQCc | NOESYd |
|---|---|---|---|---|---|
| 1 | – | – | H2, H6, H7, H8 | – | – |
| 2 | 2 | H5, H6, H7 | H5, H6, H7 | H2 | H7, H8, H11 |
| 3 | – | – | H2, H5, H11 | H3 | – |
| 4 | – | – | H2, H5, H6 | – | – |
| 5 | 5 | H2, H6 | H6 | H5 | – |
| 6 | 6 | H2, H5, H7 | H2, H5 | H6 | H7, H8 |
| 7 | 7 | H2, H6, H8 | H2, H6, H8 | H7 | H6*, H2 |
| 8 | 8 | H6', H7 | H2, H6' | H8 | H6'*, H2, H6 |
| 9 | – | – | H7, H8, H10 | H9 | – |
| 10 | 10 | – | − | H10 | – |
| 11 | 11 | – | − | H11 | H2 |
| 1' | – | – | H7', H8' | H1' | – |
| 2' | 2' | H6', H7' | H6', H7' | H2' | H7', H8'*, H11' |
| 3' | – | – | H11' | – | – |
| 4' | – | – | H2', H6', H7, H8 | – | – |
| 5' | – | – | H7, H8' | – | – |
| 6' | 6' | H7', H2', H8 | H2', H7', H8 | H6' | H8', H7', H8* |
| 7' | 7' | H2', H6', H8' | H2', H6', H8' | H7' | H6', H2', |
| 8' | 8' | H7' | H7' | H8' | H6', H2' |
| 9' | – | – | H8', H10' | – | – |
| 10' | 10' | – | – | H10' | – |
| 11' | 11' | – | – | H11' | H2' |
bgradient-selected heteronuclear multiple bond coherence;
cgradient-selected heteronuclear multiple quantum coherence;
dnuclear Overhauser effect spectroscopy.
*mean weak correlation.
Journal of the Brazilian Chemical Society
On-line version ISSN 1678-4790
J. Braz. Chem. Soc. vol.27 no.1 São Paulo Jan. 2016
http://dx.doi.org/10.5935/0103-5053.20150262
ARTICLES
Detailed 1H and 13C NMR Spectral Data Assignment for Two Dihydrobenzofuran Neolignans
Talita C. T. Medeirosa #, Herbert J. Diasa #, Eliane O. Silvaa , Murilo J. Fukuib , Ana Carolina F. Soaresb , Tapas Karc , Vladimir C. G. Helenob , Paulo M. Donatea , Renato L. T. Parreirab , Antônio E. M. Crottia *
aDepartamento
de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão
Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto-SP, Brazil
bNúcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, 14404-600 Franca-SP, Brazil
cDepartment of Chemistry and Biochemistry, Utah State University, 84322-0300 Logan-UT, United States
ABSTRACT
In this work we present a complete proton (1H) and carbon 13 (13C) nuclear magnetic resonance (NMR) spectral analysis of two synthetic dihydrofuran neolignans (±)-trans-dehydrodicoumarate dimethyl ester and (±)-trans-dehydrodiferulate dimethyl ester. Unequivocal assignments were achieved by 1H NMR, proton decoupled 13C (13C{1H}) NMR spectra, gradient-selected correlation spectroscopy (gCOSY), J-resolved,
gradient-selected heteronuclear multiple quantum coherence (gHMQC),
gradient-selected heteronuclear multiple bond coherence (gHMBC) and
nuclear Overhauser effect spectroscopy (NOESY) experiments. All hydrogen
coupling constants were measured, clarifying all the hydrogen signals
multiplicities. Computational methods were also used to simulate the 1H and 13C chemical shifts and showed good agreement with the transconfiguration of the substituents at C7 and C8.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532016000100136&lng=en&nrm=iso&tlng=en
Key words: neolignans, oxidative coupling, J-resolved, benzofurans
see..........0103-5053-jbchs-27-01-0136-suppl01.pdf
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Cavelossim, BEACH, GOA, INDIA
Top 5 best beaches Goa
Cavelossim Beach “best beach of goa to relax”
Contrast of black rocks and white sand make this Cavelossim beach a must visit tourist spot in Goa. Cavelossim is one of the less crowded beaches in Goa, so if you are seeking for a calm surrounding then tick Cavelossim in your list. Paddy fields and coconut grooves adds a different perspective to whole beach surrounding. You can also check out top unexplored beaches of India.
Cavelossim Beach Goa
The town hosts a well known beach at the southernmost tip of the Salcete beach stretch that starts from Majorda in the north to Cavelossim in the south. The Sal river flows into the Arabian Sea at the south of this town.
This town was the original above of goddess Shri Shantadurga located at Kawlem, which is one of the largest temples in the state. The idol was taken from Cavelossim to Kawlem in Ponda taluka(Antruz Mhal) during the Portuguese inquisition of Goa. Chattrapati Shahu donated money to rebuild the temple at Kawlem, as a part of donations to rebuild various temples to deities that were moved during the inquisition.Nestled between Arabian Sea and River Sal, Cavelossim Beach is one of the topmost visited beaches in Goa. It is, in fact, the most beautiful as well. Cavelossim Beach along with Varca Beach is situated south of Benaulim. The beach is, indeed, the last settlement in Salceta (southwest).Beach features: Long and wide strip. The sand is very light, almost white. It is also very soft and fine. Here and there you can find sticky black lava rocks. From the East side the beach is surrounded by beautiful palm trees and casuarinas vegetation. The water here is warm and very clean. Pitfalls on the sea floor are rare. Christmas and New Year are the most important festivals which are celebrated with full swing through the Goa.
Location: India, Goa state, South Goa, Salcette district, Cavelossim locality. The Cavelossim Beach is situated on the original peculiar peninsula formed by the passage of the River Sal, which flows into the Arabian Sea, between Varca Beach (7 km) in the north and Mobor Beach (3 km) in the south. The distance between the beach and Goa capital Panaji (or Panjim) is 50 km.Cavelossim one of the last major settlements in southwest Salcete is situated 11 km south of Colva.
Goa Cavelossim beach is filled with soft white sands and doted with black lava rocks at certain places. This beach is much bigger and cleaner and quieter than most of the famous beaches in Goa because of which it manages to attract many tourists, There are several beach shacks offering a variety of Goan dishes and seafood at reasonable price.
About The Beach
Cavelossim Beach is situated between Sal river and Arabian Sea. It is one of the most beautiful beaches in GoaCavelossim Beach Goa offers pristine beauty to its visitors. Incredible weather and magnificent views coupled with traditional Goan delicacies are sure to make your trip to Goa a memorable one.Throughout the year the climate is very pleasant.The best time to visit the amazing Cavelossim beach comprises the months of November to March.
It is surrounded by black lava rocks, which are the major attractions of the area. Moreover, the beach is the quietest of all. Thereby, honeymooners and other travelers would love to explore the sights of this beach in its serenity.The tourists can enjoy sun bathing on the beach. Dolphon trips and sunset cruises are among the other attractions at the Cavelossim Beach of Goa.
Cavelossim Beach is ideal for shell collecting, strolling, or indulging in more active pursuits like renting a kayak or catamaran.Several activities are also part of traveling to this Cavelossim Beach in Goa. Tourists can enjoy Dolphin trips, sun bathing and sunset cruises on this beach. One can also enjoy viewing the paddy fields and spectacular views of River Sal. Also,.
This beach is perfect for both intrepid explorer and casual traveler. Ideal for a romantic getaway, the place is also noted for its wonderful nightlife. Goans enjoy going out and it is not unusual to find families out for a night of merriment. In certain areas, almost every third house has a bar-cum-restaurant. The nightlife of Goa is an essential part of an average Goan's life.
Things To Do
Nature Seeing
Cavelossim Beach in Goa presents a kaleidoscopic view of the river Sal, the paddy fields and soft sandy beach. The beach seems to be the best destination for enjoying the serenity of nature.Near the mouth of the river Sal one can see a lot of men collecting oysters, mussels and clams from the river silt during the low tide.
Water Sports and Other Activities
Different types of water sports. Fishing. Boat cruises. Watching dolphins. Entertainment and informative tours and excursions around Goa. Some places offer water sports on the Sal River as well as a fishing trip in the sea, dolphin viewing or bird-watching.One can also try go karting near the seashore. Swimming zones are marked and are carefully supervised by lifeguards. There are facilities for Dolphin watching at Betty's Place as well as boat trips for Dolphin watching up river Sal
Shopping
Besides, the beach offers attractive shopping opportunities for the tourists. Shopping in Cavelossim Beach includes a wide array of Indian crafts and gift items. Tourists coming to the beach carry the crafts as souvenirs to their native land. It is a great destination for shoppers. You can buy a wide variety of Indian handicrafts, local gifts items and artifacts from local shops. You can gift these as souvenirs to your relatives and friends.
Night Life
Goan night life is much better than the nightlife of any other big metro city of India. The nightlife here was started by the hippies who came here during the 70's. Since then, the nightlife in Goa has steadily increased and has gained much fame now.
Sight Seeing
Church of Cavelossim: The Church of Cavelossim dedicated to The Santa Cruz or Holy Cross, is not too complicated in its design, yet has a charm surrounding it. It has a simple and clean facade, and is almost a mixture of its parent church designs.
Margao: Margao, nestled on the banks of the River Sal, is considered the commercial and cultural capital of the state. It is the second largest city in Goa and the administrative headquarters of South Goa. Being amongst the oldest recorded towns in Goa, it gives an opportunity to peep into the history of the state. It has some of the most famous churches and is renowned for the huge Portuguese style mansions.
Mobor, 5 km (3 miles) south of Colva, is an idyllic spot, with its backdrop of hills and the pretty fishing village of Betul nestling near the Sal River.
Goa Cabo De Rama:The Leela Beach Resort is located here. Cabo da Rama ("Cape Rama") the promontory just south of Betul, Not far from Agonda beach is Cabo de Rama, untouched by most of the visitors in this region. The atmosphere of the fort creates a sense of history and drama that very few would fail to appreciate. The fort is named after Rama, hero of the Hindu epic Ramayana. According to the local legends, Rama stayed here with his wife Sita during the period of 12 year exile.. It has the ruins of a Hindu fortress that fell to the Portuguese in 1763.
Naval Aviation Museum, Dabolim: The Naval Aviation Museum showcases the history of Indian Naval Aviation, various aircrafts, weapons, sensors, safety equipment, rare photographs depicting Goa's liberation and artifacts. A multimedia games section is an added attraction. The museum is situated in the picturesque backdrop of the Bogmalo beach.
What to Eat and Drink
There are numerous beach shacks offering a variety of Goan dishes and seafood at reasonable prices. There are several food joints around Dona Sylvia where you can get entire package of good food, good drink, and a pleasant service at quite reasonable rates
There are a number of multicuisine restaurants that specialize in seafood, Goan cuisine and grill vegetarian dishes. There are also many places to shop for books, trendy clothes and other souvenirs. They are offered by Shacks which are placed all alongside the beach. Deck-chairs and umbrellas are free. The food is tasty, delicious, varied and not so expensive. Fresh cool drinks are also offered here everywhere.
How to reach
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