Calciferol and its relatives. Part 19. Synthetic applications of cyclic orthoesters: stereospecific synthesis of a bicyclic alcohol related to the vitamins D2
- 1 January 1977
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- No. 10,p. 1211-1218
- https://doi.org/10.1039/p19770001211
Abstract
Examples are described of Claisen rearrangements using cyclic orthoesters. Their synthetic potential is pointed out and illustrated by a synthesis of the optically active 1β-[(R)-2-hydroxy-1-methylethyl]-3aα,6,7,7aβ-tetrahydro-7aβ-methylindane (31), a compound intended as an intermediate for syntheses of vitamin D2 and 25-hydroxyvitamin D3. In the key reaction between 2-hydroxy-4-methylcyclohex-3-enyl benzoate (7) and 2,2-diethoxy-4-methyltetrahydrofuran (24) the asymmetric centre C-1 of the final product (31) is set up stereospecifically by asymmetric induction with the required configuration, and this configuration is maintained throughout the synthesis.This publication has 0 references indexed in Scilit: