Fig. 1: Brønsted acid-catalysed cyclization of neral to (1R,6S)-trans-isopiperitenol.
From: Catalytic asymmetric synthesis of cannabinoids and menthol from neral
a, Selectivity problems in the cyclization of neral named the ‘neral to isopiperitenol dilemma’ and isopiperitenol as valuable chiral pool material in the synthesis of cannabinoids and menthol. b, The first asymmetric, selective cyclization of neral to isopiperitenol under confined Brønsted acid catalysis.
