𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Rearrangement of 6,7-dithiabicyclo[3.1.1]heptane 6-oxides to a 7,8-dithia-6-oxabicyclo[3.2.1]octane catalyzed by montmorillonite K 10

✍ Scribed by Akihiko Ishii; Yi-Nan Jin; Masamatsu Hoshino; Juzo Nakayama

Publisher
John Wiley and Sons
Year
1995
Tongue
English
Weight
456 KB
Volume
6
Category
Article
ISSN
1042-7163

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Treatment of 2,2,4,4‐tetramethyl‐1,5‐diphenyl‐6,7‐dithiabicyclo[3.1.1]heptane 6‐endo‐oxide (2) with Montmorillonitc K 10 in dichloromethane gave 2,2,‐4,4‐tetramethyl‐1,5‐diphenyl‐7,8‐dithia‐6‐oxabicyclo‐[3.2.1]octane (6) (11%) with recovery of 2 (87%). Under similar reaction conditions, the 6‐exo‐oxide 7 and the sulfenate 6 gave a mixture of 6 (21%), 2 (67%), and 7 (9%) and a mixture of 2 (89%) and 6 (9%), respectively. These results indicate the relative thermodynamic stabilities of the three compounds to be 2 > 6 > 7. PM3 calculations on these compounds showed the heats of formation (kcal/mol) to be in the following order: 6 (44.12783), 2 (57.46721), and 7 (59.37918). The driving force of this unusual 1,2‐rearrangement of 2 and 7 to 6 would be the release of the ring strain of the bicyclo[3.1.1]heptane system of 2 and 7 by ring expansion.

📜 SIMILAR VOLUMES

Enzymes in Organic Synthesis, 8. Synthes
Enzymes in Organic Synthesis, 8. Synthesis of enantiomerically pure prostaglandin intermediates by enzymatic transesterification of (1S*,5R*,6R*,7R*)-(±)-7-hydroxy-6-hydroxymethyl-2-oxabicyclo[3.3.0]octan-3-one
✍ Weidner, Judith ;Theil, Fritz ;Kunath, Annamarie ;Schick, Hans 📂 Article 📅 1991 🏛 John Wiley and Sons 🌐 English ⚖ 271 KB

## Abstract Lipase Amano PS is a suitable biocatalyst for the highly regio‐ and enantioselective transesterification of the racemic prostaglandin building block (1__S__~\*~,5__R__\*,6__R__\*,7__R__\*)‐(±)‐7‐hydroxy‐6‐hydroxymethyl‐2‐oxabicyclo[3.3.0]octan‐3‐one (__rac__‐1) yielding (1__S__,5__R__,6

Cyclization of ethyl (E)/(Z)-[2-(1-cyclo
Cyclization of ethyl (E)/(Z)-[2-(1-cyclohexen-1-yl)cyclohexylidene]cyanoacetate to 10-amino-1,2,3,4,5,6,7,8-octahydrophenanthrene-9-carboxylic acid — a route to 1,2,3,4,5,6,7,8-octahydrophenanthrene derivatives
✍ Wilamowski, Jaroslaw ;Krasodomski, Wojciech ;Nowak, Barbara ;Sepioł, Janusz J. 📂 Article 📅 1995 🏛 John Wiley and Sons 🌐 English ⚖ 389 KB

## Abstract Cyclization of ethyl (__E__)/(__Z__)‐[2‐(1‐cyclohexen‐1‐yl)cyclohexylidene]cyanoacetate (2) in cold concentrated sulfuric acid affords 10‐amino‐1,2,3,4,5,6,7,8‐octahydrophenanthrene‐9‐carboxylic acid (4) and 3,5,6,7,8,8a‐hexahydro‐3‐oxospiro‐[1__H__‐2‐benzopyran‐1,1′‐cyclohexane]‐4‐carb