Authors' reply

Abstract

α,α′‐Diactivated cyclic‐ or acyclic ketones undergo a chemoselective base promoted (K2CO3, DBU) one‐pot C−C cycloalkylation, with 1,3‐ and 1,4‐dihalides having a cis‐like fixed configuration. This reaction gives highly functionalized bicyclo[3.2.1]octan‐9‐one and bicyclo[4.2.1]nonan‐9‐one derivatives, which are easily transformed to seven‐ and eight‐membered rings through a high yield retro‐Dieckmann cleavage. Starting from trans‐1,4‐dibromo‐2‐butenes, the transformation is governed by stereoelectronic factors and leads, through a chemo‐ and stereoselective C−O cycloalkylation, to synthetically valuable monocyclic or fused polycyclic functionalized enol ethers of high synthetic value. Semiempirical calculations showed a small difference in energy and the late character of the transition states leading to cis and trans isomers of the corresponding fused polycyclic enol ethers. These results, although minimizing the influence of a destabilizing 1,3‐interaction on the outcome of the reaction, are qualitatively in agreement with the experimental results.

An Unusual Case of Primary Small Cell Neuroendocrine Carcinoma of the Breast

“…The reported age of incidence is from 40 to 70 years, with a higher incidence over 60 years of age. All the tumors described showed morphological and immunohistochemical similarities to the breast metastases of pulmonary small cell carcinoma, the most distinguishing feature are the absence of primary small cell cancer elsewhere (4,6). The histogenesis is not clear, because the neuroendocrine cells in normal breast have not been proven conclusively (17,18).…”

“…It has been suggested that SCNC of breast is a variant of metaplastic carcinoma arising from usual lobular or ductal carcinoma because of its dimorphic picture (4). However other authors believe that SCNC is a distinct type of breast carcinoma different from the usual types of carcinoma, with variable degrees of neuroendocrine differentiation which carries worse prognosis (2,6). Some authors claim that the presence of an in situ carcinoma, with areas of ductal, lobular, or papillary differentiation within the breast is highly suggestive of a primary breast rather than a metastatic tumor (6,8,9), however this criterion was not met in most published descriptions of this rare tumor (10).…”

“…Most studies have shown that the SCNC of breast is very aggressive neoplasm and has poorer prognosis than usual ductal type (2,5,6). However, Shin et al (4) noted that the patients with SCNC of breast may have a good prognosis, depending on the initial stage of the disease.…”

“…Contrary to pulmonary small cell carcinomas, extra pulmonary tumors of this type are very uncommon. Reports also suggest that clinical course of extrapulmonary SCNC is as aggressive as its pulmonary counterpart (5,6). Herein we discuss an interesting case of a SCNC of breast with emphasis in the, clinico‐pathological findings as well as differential diagnosis and treatment options.…”