This work describes the preparation of the C(7)-C(20) fragment of spirotoamides A to C in a very elegant fashion, achievement very high levels of stereocontrol. The synthesis has been accomplished by a sequence involving 14 steps (0.36% overall yield, average of 81% for each step) in high diastereo and enantioselectivity, employing, as determining steps, asymmetric Mukaiyama and boron-mediated 1,5-anti promoted aldol reactions between α-methyl-β-hydroxyketones and aldehydes.

An electrophilic iodocyclization reaction involving alkynylated 2-iodoanisoles and molecular iodine in the presence of sodium bicarbonate was developed and diiodo-functionalized benzo[b]furans were obtained in yields from 45 to 99%.

A reação de acoplamento entre 2,6-diiodoanisóis e alcinos terminais usando Pd(PPh3)2Cl2 e CuI como catalisadores e diisopropilamina como base em tolueno a temperatura ambiente por 12 h produziu seletivamente 2-iodoanisóis aquinilados, em rendimentos de bons a excelentes (52-95%), os quais são blocos de construção úteis com potencial aplicação na síntese de benzo[b]furanos funcionalizados.

The coupling reaction between 2,6-diiodoanisoles and terminal alkynes using Pd(PPh3)2Cl2 and CuI as catalysts and diisopropylamine as base in toluene at room temperature for 12 h produced selectively alkynylated 2-iodoanisoles, in good to excellent yields (52-95%), which are useful building blocks with potential application in the synthesis of functionalized benzo[b]furans.