Iodine in Dichloromethane - A Simple Method for Selective Cleavage of Prenyl Ethers
作者:Jean-Michel Vatèle
DOI:10.1055/s-2001-18765
日期:——
Treatment of prenyl (Pre) ethers of simple alcohols, carbohydrates, steroids, with I2 in CH2Cl2 in the presence of 3Å molecular sieves, constitutes an effective method for their deprotection. This method tolerates other etheral functionalities such as acetals, allyl, t-butyldiphenylsilyl or benzyl groups as well as base labile groups such as acetates. This method applied to a prenyl aryl ether gave rise to a 2,2-dimethylchroman derivative in an acceptable yield.
The prenyl group: a versatile hydroxy protecting group, removable chemoselectively under mild conditions
作者:Jean-Michel Vatèle
DOI:10.1016/s0040-4020(02)00539-2
日期:2002.7
6-dicyanoquinone (DDQ) in dichloromethane–water (9:1) are mild and efficient methods to cleave prenyl ethers. These reaction conditions are compatible with the presence of other protectinggroups such as acetals, acetates, allyl, benzyl and TBDPS groups. Exposure of aryl prenyl ethers to iodine led to the formation of 3-iodo-2,2-dimethylchroman derivatives in acceptable yields via a tandem Friedel–Crafts/iodocyclization
An Efficient and Chemoselective Cleavage of Prenyl Ethers with DDQ
作者:Jean-Michel Vatèle
DOI:10.1055/s-2002-20480
日期:——
temperature with DDQ in dichloromethane-water (9:1). The reaction conditions are compatible with the presence of other ethereal functionalities such as acetonides, allyl, benzyl, TBS, TBDPS groups. We have also shown that deprotection of prenyl ethersusing a catalyticamount of DDQ in the presence of 3 equivalents of Mn(OAc) 3 is a good alternative for the use of a stoichiometric amount of DDQ, albeit the