documentclass[pdftex,12pt,a4paper,twoside]{article}

usepackage{adjustbox}
usetikzlibrary{arrows,chains,matrix,positioning,scopes,snakes,cd}

begin{document}

[adjustbox{scale=0.9,center}{
begin{tikzcd}[font=small, row sep=1.2em]
cdots arrow{r} & overset{large{K_*(A)}}{underset{large{K_*(B)}}{otimes}}arrow{r} arrow{d}
 {alpha(A,B)}[swap]{cong} & overset{Large{K_*(A)}}{underset{Large{K_*(B)}}{otimes}} arrow{r} arrow{d}
{alpha(A,B)}[swap]{cong}& overset{large{K_*(A)}}{underset{large{K_*(Brtimes_varphimathbb{Z})}}{otimes}} arrow{r} arrow{d}{alpha(A,Brtimes_varphimathbb{Z})}
 & overset{Large{K_{*}(A)}}{underset{Large K_{*-1}(B)}{otimes}} arrow{r}arrow{d}{alpha(A,B)}[swap]{cong} & cdots \
 cdots arrow{r} & K_*(Aotimes B) arrow{r} & K_*(Aotimes B) arrow{r} & tiny{K_*(Aotimes (Brtimes_varphimathbb{Z}))} arrow{r} & tiny{K_{*-1}(Aotimes B)} arrow{r} & cdots
 end{tikzcd}
 }]
end{document}