[reaction: see text]. Photochromic pyrans, including [3H]naphtho[2,1-b]pyrans, [2H]naphtho[1,2-b]pyrans, indeno-fused naphtho[1,2-b]pyrans, and heteroannulated pyrans, were synthesized in excellent yields through a facile one-pot procedure by reaction of propargyl alcohol and naphthol or phenol derivatives in the presence of 5 mol % PPTS and 2 equiv of (MeO)3CH. Symmetrical and nonsymmetrical bispyrans
[反应:请参见文字]。合成了包括[3H]
萘[2,1-b]
吡喃,[2H]
萘[1,2-b]
吡喃,
茚并稠合的
萘[1,2-b]
吡喃和异环
吡喃的光致变色
吡喃。在5 mol%P
PTS和2当量(MeO)3CH存在下,通过炔
丙醇与
萘酚或
苯酚衍
生物反应,通过简便的一锅法获得优异的收率。对称和非对称双
吡喃也可以使用该方案制备。