Scheme 2. Control experiments. (a) The reaction of pre-prepared p-QM. (b) The reaction of methyl-protected propargylic alcohol 2′. (c) Synthesis of chiral tetrasubstituted allene 4. (d) The dearomative Diels–Alder reaction under either standard or catalyst-free consitions. (e) The dearomative 1,8-addition in the precence of 10 mol% of pyridine.
