An Access to erythro-Diols via Sharpless's Asymmetric Dihydroxylation Reaction
摘要:
A method has been developed to access erythro-2,3-diols via Sharpless's asymmetric dihydroxylation reaction. Thus, a TBDMS-protected (E)-allylic alcohol is dihydroxylated and the resulting threo-2,3-diol is converted to the cyclic sulfate. Upon desilylation, this compound undergoes a Payne-type rearrangement. Nucleophilic epoxide-opening then provides an erythro-2,3-diol. The conversions from the cyclic sulfate to the diol product are performed in a single reaction vessel. Due to the irreversible nature of the Payne-type rearrangement, this process is easy to perform and completely regioselective independent of the substrate structures. Also, being performed in THF, the process is compatible with a variety of nucleophiles, including thiolates, N--(3), (OAc)-O--, (CN)-C--, halides as well as carbon nucleophiles and hydride.
Reaction of enantiopure epoxides (1) with NO occurred highly stereoselectively, affording syn-ring opened products, nitrates (2). The configuration of 2 was confirmed to be retained by determining the configuration of reduced products 1,2-glycols (4) from 2. A possible mechanism is suggested to trace out the syn-ring opening pathway.
Enantioselective synthesis of goniobutenolides A and B
作者:Soo Y. Ko、Joanne Lerpiniere
DOI:10.1016/0040-4039(95)00166-a
日期:1995.3
Goniobutenolides A and B were synthesized in the enantiopure Forms, employing the asymmetric dihydroxylation and cyclic sulfate rearrangement-opening reactions as the key stereocenter-forming steps.
Ko Soo Y., Malik Majbeen, Dickinson A. Frances, J. Org. Chem, 59 (1994) N 9, S 2570-2576