A concise effective deprotection of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-one
摘要:
An effective deprotective method of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-ones using alkyl vinyl ether in the presence of protic acid followed by the treatment of aqueous alkali was described. This novel protocol could be fulfilled under mild condition with high yield. The mechanism mediated by a carbonium ion formed in situ was clarified by the capture of the cleaved fragment. (c) 2006 Elsevier Inc. All rights reserved.
A concise effective deprotection of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-one
摘要:
An effective deprotective method of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-ones using alkyl vinyl ether in the presence of protic acid followed by the treatment of aqueous alkali was described. This novel protocol could be fulfilled under mild condition with high yield. The mechanism mediated by a carbonium ion formed in situ was clarified by the capture of the cleaved fragment. (c) 2006 Elsevier Inc. All rights reserved.
A concise effective deprotection of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-one
作者:Bei Na Zhang、Ying Chen、Qian Zhang、Peng Xia
DOI:10.1016/j.steroids.2006.10.008
日期:2007.1
An effective deprotective method of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-ones using alkyl vinyl ether in the presence of protic acid followed by the treatment of aqueous alkali was described. This novel protocol could be fulfilled under mild condition with high yield. The mechanism mediated by a carbonium ion formed in situ was clarified by the capture of the cleaved fragment. (c) 2006 Elsevier Inc. All rights reserved.