Our interest in the preparation of structurally diverse heterosteroids lead to a need for a facile flexible strategy, in which a common intermediate can be used in a conjunctive fashion to form an array of N-heterocycles attached or fused to the steroid core. Hence, we turned to β-chlorovinyl aldehydes, which are readily available by the Vilsmeier–Haack reaction (Tasneem, 2003) and proved to be highly reactive ambident electrophiles (Bera et al., 2008; Bezboruah et al., 2013; Brockmeyer et al., 2014; Kroger et al., 2015). Recently, we have reported the synthesis of steroidal pyridazines (Komkov et al., 2015; Volkova et al., 2016), thiadiazoles (Zavarzin et al., 2013), and 4,5-disubstituted pyrimidines (Komendantova et al., 2017) via condensation of β-chlorovinyl aldehydes with bis-nucleophiles such as oxamic acid thiohydrazides and amidines. Based on these results, we accomplished the efficient synthesis of heterosteroids possessing a six-membered N-heterocycle attached or fused to the A/D ring of the steroid core starting from readily available materials. Thus, the synthesis of derivatives of the androstene and estrane series containing A-/D-ring annulated pyrimidine (Schemes 1, 3a–f) or linked dihydrotriazine (Schemes 1, 4a–c) moieties was accomplished starting from natural hormones 1a–c (estrone, dihydrotestosterone, and dehydroepiandrosterone) by the general two-step sequence involving: (1) the Vilsmeier–Haack reaction giving steroidal β-chlorovinyl aldehydes 2a–c, (2) the condensation of the former with amidines (Scheme 1).