Answer to Question #71347 in Organic Chemistry for zetabyte

Question

what is the arrow pushing mechanism for

(4aS,5S)-5-hydroxy-4a-methyl-4,4a,5,6,7,8-hexahydronaphthalen-2(3H)-one

reacting with

ethane-1,2-diol

TsOH

to produce

2-((4-methyl-5,6,7,8-tetrahydronaphthalen-1-yl)oxy)ethan-1-ol

Answer 1

This reaction should have been typical ketalization, but, probaly, went through few rearrangements under acidic conditions. The driving force of this reaction is aromatization of six-membered ring which is highle desirable.