REACTION OF 1-ADAMANTYL CATION WITH CARBON MONOXIDE IN THE PRESENCE OF ADAMANTANE AND TRIFLUOROMETHANESULFONIC ACID: A CONVENIENT ROUTE TO 3,4-HOMOADAMANTANEDIOL

Article abstract of DOI:10.1016/S0040-4020(01)90004-3

The carbonylation of the 1-adamantyl cation with carbon monoxide in carbon tetrachloride at atmospheric pressure in the presence of trifluoromethanesulfonic acid (triflic acid) and adamantane affords 3-hydroxy-4-homoadamantyl 1-adamantanecarboxylate (2) in 70percent yield under appropriate conditions.Among various 1-adamantyl cation precursors tested, 1-adamantyl trifluoromethanesulfonate (triflate) and methanesulfonate (mesylate) have given the best, comparable results.As to the acid catalyst, fluorosulfonic acid is less effective than triflic acid, and 100percent sulfuric acid a nd methanesulfonic acid are completely ineffective to produce 2.It is recommended to use five mol each of triflic acid and adamantane per mol of 1-adamantyl mesylate or triflate.This reaction proceeds via the addition of the 1-adamantanecarbynol cation to 1-adamantanecarbaldehyde, a transient intermediate, followed by the Wagner-Meerwein rearrangement.The hydroxy ester 2 is easily converted into 3,4-homoadamantanediol which is a promising starting material for 3,4-bifunctional homoadamantane derivates.